It's the economy, again - a sign of the times and perhaps the times to come. Michigan voters, who in 2006 went to the polls disillusioned by the war in Iraq, angry about runaway federal spending and disgusted by the performance of the Bush administration, Tuesday cast their ballots mostly with their pocketbooks in mind.

The optimistic economic message former Massachusetts Gov. Mitt Romney brought to his native state was a big reason he finished on top of Tuesday's Republican primary here. A solid majority of both Republican and Democratic primary voters said their motivating issue was the economy, according to the National Election Pool exit poll.

The vote reflects the increasing anxiety of Michigan residents who have waited five years for a turnaround that never seems to arrive.

It also indicates that a candidate such as Romney, who speaks of hope for a brighter future, can find legs in a campaign in which voters are so far lukewarm about the choices. Romney promised brighter prospects for the vital automotive industry. Though he was derided for being Pollyannaish, the message resonated. Michigan was a must-win state for Romney, and he spent more than $2 million to ensure his victory. Leaving Michigan, it's up to Romney to go on to South Carolina, Florida and Super Tuesday and prove he is the candidate who can sustain momentum. So far, in three major primaries and caucuses, GOP voters have chosen three different candidates.

Arizona Sen. John McCain, who mounted an aggressive campaign here with comparatively meager resources, can learn something from his Michigan defeat. Straight talk about the tough economic conditions must be matched with a blueprint for making things better. McCain must beef up the solutions side of his message. The economy is not likely to be a fleeting issue. Early indicators are that it will be the battleground on which the fall campaign is fought. Asked to explain why they were motivated by economic concerns, roughly two-thirds of Republicans said they see the economy as either not so good or poor.

And yet most don't feel they are at immediate risk. Two-thirds said their households are holding steady financially, and of the remainder, about an equal number said they are getting ahead as said they are falling behind.

But it clearly doesn't matter whether they are personally dealing with an economic crisis, or which direction the economic indicators are pointing. Voters are worried about their family finances and are looking for candidates who can calm their fears.

The Michigan campaign should be good practice for the candidates. The state has a five-year head start on the economic worries now capturing the attention of the rest of the nation.

Certainly, other issues are still important. The war and terrorism still show up on the list of concerns. But voters who support the Iraq war still chose Romney and his economic appeal over McCain. Voters are willing to ignore other differences if a candidate scores on the economy.

Michigan and the industrial Midwest will be key in determining who wins the presidency.

The candidates came here in January prepared to talk about the economy. When they return in the fall, they must bring sharpened answers to the growing questions voters will have about pocketbook issues.